JP2011111954A - Fastening structure between cylinder block and cylinder head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a thickness of a barrier wall of a cylinder head for partitioning a side part cooling water passage around a combustion chamber and an upper part cooling water passage, and sufficiently transmit fastening axial force of a fastening bolt of the cylinder block and the cylinder head to a seal part between the cylinder block and the cylinder head between the side part cooling water passage and the combustion chamber, by the barrier wall. <P>SOLUTION: The barrier wall 7 between the upper part cooling water passage 2 of the cylinder head 3 and the side part cooling water passage 5 is stretched between the bolt fastening seat 8 of the cylinder head 3, and the seal part 9 between the cylinder block 4 and the cylinder head 3 between the side cooling water passage 5 and the combustion chamber 1. The barrier wall 7 is in a stretched form in which the fastening axial force of the bolt 6 for fastening between the cylinder block 4 and the cylinder head 3 is transmitted to the seal part 9. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fastening structure between a cylinder block and a cylinder head in an engine for automobiles and the like, and more particularly, to a fastening structure between a cylinder block and a cylinder head that form a cooling water passage around a side periphery of a combustion chamber. .

  Such a fastening structure between the cylinder block and the cylinder head is known from Patent Document 1 below. In this patent document, a bolt is fastened in a state where a cooling water passage is formed around a side circumference of a combustion chamber communicating with a cylinder block between a cylinder head having a cooling water passage located above the combustion chamber and a cylinder block via a gasket. The technology to do is disclosed.

  Although Patent Document 1 does not specifically disclose the fastening structure between the cylinder block and the cylinder head, the present applicant has conventionally adopted a fastening structure between the cylinder block and the cylinder head as shown in FIG. Yes. Specifically, the circumference of the combustion chamber a side between the cylinder head c that forms the upper coolant passage b on the combustion chamber a and the flange walls c1 and d1 that extend outward from the combustion chamber a with the cylinder block d. The side cooling water passage e is formed, and the flange walls c1 and d1 are fastened by bolts f around the outer side of the side cooling water passage e to connect both the cylinder head c and the cylinder block d. In such a fastening structure, the fastening axial force by the fastening bolts f is between the flange walls c1 and d1 around the outer side of the side cooling water passage e regardless of whether or not a gasket is interposed between the cylinder block d and the cylinder head c. However, it is difficult to reach the seal part h which is desired to fit the inner side of the side cooling water passage e, that is, the seam to the combustion chamber a, whereas the thickness t of the flange wall c1 of the cylinder head c By increasing, it is possible to sufficiently apply the fastening axial force to the seal portion h to ensure a necessary seal.

Japanese Utility Model Publication No. 59-60346

  However, the fastening structure between the cylinder block and the cylinder head as shown in FIG. 4 implemented by the present applicant is that the partition wall i between the upper cooling water passage b and the side cooling water passage e formed by the flange wall c1. This increases the thickness t, which narrows the area of the combustion chamber a facing the upper cooling water passage b and the side cooling water passage e, and the partition wall i increases the amount of heat stored in proportion to the increase in the thickness t. As a result, the cooling effect, particularly around the upper part of the combustion chamber, is reduced, causing knocking and also a problem of lowering fuel consumption.

  In view of such a problem, the present invention suppresses the thickness of the partition wall of the cylinder head that partitions the side cooling water passage and the upper cooling water passage around the combustion chamber, and fastens the cylinder block and the cylinder head by the partition wall. It is an object of the present invention to provide a cylinder block and cylinder head fastening structure that can sufficiently transmit the bolt fastening axial force to the cylinder block between the side cooling water passage and the combustion chamber and the cylinder head seal portion.

  In order to solve the above problems, the cylinder block / cylinder head fastening structure according to the present invention has a side portion around the combustion chamber side circumference between the cylinder head and the cylinder block in which an upper cooling water passage is formed on the combustion chamber. A cooling water passage is formed, and a cylinder block and a cylinder head are fastened with bolts between the cylinder block and the cylinder head around the outside of the side cooling water passage. The partition wall between the water passages is stretched between the bolt fastening seat of the cylinder head and the cylinder block between the cooling water passage and the combustion chamber and the seal between the cylinder heads, and the bolt that fastens between the cylinder block and the cylinder head. This is characterized in that the fastening axial force is transmitted to the seal portion.

  In such a configuration, the cylinder head and the cylinder block are fastened by bolts around the outer side of the side cooling water passage around the combustion chamber side circumference formed between them. A partition wall of the cylinder head that partitions the upper cooling water passage on the combustion chamber to be formed includes a bolt fastening seat of the cylinder head, a cylinder head and a cylinder block seal portion between the side cooling water passage and the combustion chamber, , The fastening axial force of the bolt can be transmitted to the cylinder block between the side cooling water passage and the combustion chamber and the seal portion between the cylinder heads without bending.

  According to the fastening structure between the cylinder block and the cylinder head of the present invention, the axial force of the bolt that fastens the cylinder head and the cylinder block around the outer periphery of the side cooling water passage around the combustion chamber side circumference formed between them. The cylinder head bolt fastening seat by the partition wall between the side cooling water passage and the upper cooling water passage of the cylinder head, and the cylinder head and cylinder block seal portion between the cooling water passage and the combustion chamber. By the tension action, the cylinder block and the cylinder head seal portion between the side cooling water passage and the combustion chamber are reliably transmitted without escape due to bending. Therefore, the partition wall only needs to secure a buckling strength against the transmitted axial force, and the partition wall portion is thinned, contributing to weight reduction, reducing the heat capacity, and facing the upper cooling water passage and the side cooling chamber of the combustion chamber. The area can be increased to increase the cooling effect around the top of the combustion chamber. As a result of this cooling effect improvement, knocking can be prevented and fuel consumption reduction due to knocking can be suppressed.

Sectional drawing which shows one specific example of the cylinder block which concerns on embodiment of this invention, and the fastening structure between cylinder heads. The partial perspective view around the cylinder head of the engine which shows the fastening structure. Sectional drawing which shows the modification of the fastening structure. It is sectional drawing which shows the cylinder block which is the conventional implementation goods, and the fastening structure between cylinder heads.

  Specific examples of the cylinder block and cylinder head fastening structure according to the present embodiment according to the present embodiment will be described with reference to FIGS. 1 to 3 to provide an understanding of the present invention.

  The cylinder block / cylinder head fastening structure of the present embodiment has an upper cooling water passage on the combustion chamber 1 formed in the upper part of the cylinder bore 1 as in the example shown in FIGS. 1 and 2 and the example shown in FIG. The side cooling water passage 5 around the combustion chamber 1 side periphery is formed between the cylinder head 3 having the cylinder 2 and the cylinder block 4 having the cylinder bore 10, and the cylinder block is formed outside the side cooling water passage 5. 4. It has a basic structure that follows the conventional structure in which the cylinder head 3 is fastened with bolts 6. As an improved structure for this, in particular, the partition wall 7 partitioning the upper cooling water passage 2 and the side cooling water passage 5 of the cylinder head 3 is replaced with the bolt fastening seat 8 of the cylinder head 3 and the side cooling water passage. 5 and the seal portion 9 between the cylinder block 4 and the cylinder head 3 between the combustion chamber 1 and the fastening axial force of the bolt 6 that fastens the cylinder block 4 and the cylinder head 3 to each other. 9 is in the form of a brace that is transmitted to 9.

  As a result, the cylinder head 3 and the cylinder block 4 are fastened by the bolt 7 with the axial fastening force F around the outer side of the side cooling water passage 5 around the combustion chamber 1 side circumference formed between them. Of course, the seal pressure of the seal portion 11 between the cylinder head 3 and the cylinder block 4 outside the side cooling water passage 5 near the position can be secured, and the side cooling water passage 5 and the cylinder head 3 form. A partition wall 7 of the cylinder head 3 between the upper cooling water passage 2 on the combustion chamber 1 and a bolt fastening seat 8 of the cylinder head 3 and between the cylinder head 3 and the cylinder block 4 between the cooling water passage and the combustion chamber. The fastening axial force F of the bolt 6 is applied to the seal portion 9 between the cylinder block 3 and the cylinder head 4 between the side cooling water passage 5 and the combustion chamber 1. , It can be transmitted not escape by himself.

  Thus, according to the present embodiment, the bolt 6 is fastened to fasten the cylinder head 3 and the cylinder block 4 around the outer periphery of the side cooling water passage 5 around the combustion chamber 1 formed around them. The cylinder head and the cylinder between the bolt fastening seat of the cylinder head and the cooling water passage and the combustion chamber by the partition wall 7 that the axial force F partitions the side cooling water passage 5 and the upper cooling water passage 2 of the cylinder head 3. By the tension action between the block-to-block seal part, it is reliably transmitted to the seal part 9 between the cylinder block 3 and the cylinder head 4 between the side cooling water passage 5 and the combustion chamber 1 without escaping due to bending. Is done. Therefore, the partition wall 7 only needs to secure a buckling strength with respect to the transmitted fastening axial force F1, and the partition wall 7 is thinned, contributing to weight reduction and lowering the heat capacity, and the upper cooling water passage 2 and side of the combustion chamber 1 By increasing the area facing the partial cooling chamber 5, the cooling effect particularly around the upper portion of the combustion chamber 1 can be enhanced. As a result of the improvement of the cooling effect, it is possible to prevent the occurrence of knocking and to suppress the reduction in fuel consumption due to knocking.

  As shown in the figure, the partition wall 7 may be made thinner by making the thickness T smaller than the thickness of the ceiling wall of the combustion chamber 1 formed by the cylinder head 3. As a result, the thickness T1 of the portion where the partition wall 7 of the cylinder head 3 is connected to the ceiling wall of the combustion chamber 1 by the seal portion 9 is particularly thin as compared with the conventional case. This is advantageous in improving the cooling effect by expanding the area facing the passage 2 and the upper side cooling water passage 5.

  Here, the transmission force of the fastening axial force F to the seal portion 9 between the cylinder block 3 and the cylinder head 4 between the side cooling water passage 5 and the combustion chamber 1 is equal to the fastening axial force F shown in FIG. The force F1 acts in the direction in which the partition wall 7 is stretched.

  Based on this, in the example of FIGS. 1 and 2, the partition wall 7 faces the buckling deformation as a straight tension form between the two points A and B where the fastening axial force F1 works.

  On the other hand, in the example shown in FIG. 3, the passage cross-sectional area of the upper cooling water passage 2 is increased by curving into a convex arch shape between the two points A and B toward the side cooling water passage 5. . However, since the buckling strength with respect to the fastening axial force F1 is lowered when curved in the arch shape, the reinforcing rib 12 parallel to the direction in which the fastening axial force F1 acts is formed in the curved portion as shown in the figure. The reinforcing rib 12 causes the volume of the partition wall 7 to be increased, but the thickness T of the partition wall 7 can be further reduced, so that it can be almost offset. The curved direction of the partition wall 7 may be convex toward the upper cooling water passage 2 side.

  The side cooling water passage 5 is formed in a so-called glasses shape in which the cylinder bores 10 adjacent to each other around the combustion chamber 1 are connected to each other between the combustion chambers 1. As shown in FIG. 2 along the spectacles form, the fastening axial force F1 is transmitted to the seal portion 9 even between the fastening positions of the bolts 6 indicated by the bolt through holes 21 and the bolt screw alignment holes 22 in FIG. To act. Here, the buckling strength can be increased by forming a wave-like shape in the continuous direction of the peripheral wall formed by the partition wall 7.

  The present invention can be practically used in a fastening structure between an engine cylinder block and a cylinder head, and suppresses the thickness of the partition wall of the cylinder head that partitions the cooling water passage around the side periphery of the combustion chamber and the cooling water passage above the combustion chamber, Moreover, the partitioning force of the bolt between the cylinder block and the cylinder head can be sufficiently transmitted to the cylinder block and the cylinder head seal portion between the side cooling water passage and the combustion chamber.

Reference Signs List 1 Combustion chamber 2 Upper cooling water passage 3 Cylinder head 4 Cylinder block 5 Side cooling water passage 6 Bolt 7 Partition 8 Bolt fastening seats 9 and 11 Sealing portion 12 Reinforcement rib

Claims (1)

A side cooling water passage around the combustion chamber side circumference is formed between the cylinder head formed with the upper cooling water passage on the combustion chamber and the cylinder block, and the cylinder block and cylinder head are formed outside the side cooling water passage. It is a cylinder block and a cylinder head fastening structure that are fastened with bolts,
Stretch the partition between the upper coolant passage and the side coolant passage of the cylinder head between the bolt fastening seat of the cylinder head and the cylinder block between the coolant passage and the combustion chamber and the seal between the cylinder heads. A fastening structure between the cylinder block and the cylinder head, wherein the fastening force is such that a fastening axial force of a bolt that fastens the cylinder block and the cylinder head is transmitted to the seal portion.

Images